BIO 3124 Lecture Notes - Lecture 15: Cytopathic Effect, Hemagglutination, Obligate Parasite
Document Summary
Obligate parasite: no metabolism or activity without host. Nb: multiply, not reproduce - reproduction is for living things and people don"t consider viruses living. Most cellular organisms contain both at some point, but viruses only contain one. Protects the genome from physical, chemical, and enzymatic conditions. Has receptor proteins (spikes) that enable the recognition and attachment to the host cell. Naked viruses: spikes are found on the nucleocapsid. Enveloped viruses: spikes are found on the envelope: capsid is surrounded by a lipid bilayer. Morphology of protein coat (capsid: helical (ex. Ebola: isometric or polyhedral (ex. in uenza, pleomorphic (ex. bacteriophages, nb: protein subunits are called capsomeres. Presence or absence of envelope: enveloped vs. naked viruses. Genome: ssdna vs. dsdna vs. ssrna vs. dsrna, circular or linear. Groups: i. dsdna, ii. ssdna, iii. dsrna, iv. +ssrna: coding rna viruses, sense rna viruses: v. -ssrna: non-coding rna viruses, anti-sense ran viruses, vi.